Rock crystal, a rare mineral and a type of gemstone, belongs to the quartz family in mineralogy. Its main chemical component is silica, with the chemical formula SiO2. When pure, it forms colorless and transparent crystals. When containing trace elements such as Al and Fe, it appears purple, yellow, brown, etc. After irradiation with trace elements, it forms different types of color centers, producing different colors such as purple, yellow, brown, pink, etc.
Minerals containing associated inclusions are called inclusion crystals, such as crystals and green ghosts, with inclusions such as rutile, tourmaline, actinolite, mica, chlorite, etc.